Whether the UK’s implementation of the separation of powers reflects the core features
and values of the doctrine is contentious. This essay endeavours to argue contrary to the
interpretation that the doctrine is effectuated ‘half-heartedly’, instead, contending a
deliberate failure of implementation due to its incompatibility with parliamentary
sovereignty. However, there is no doubt as to the effectiveness and clarity of the doctrine of
judicial independence due to its statutory foundation and normative obligation.
This essay will first explore the features, aims and theories of the separation of powers,
determining whether it can coexist with parliamentary sovereignty. The constitutionally
problematic overlaps between the governmental branches will then be analysed regarding
their compatibility with the separation of powers. Lastly, this essay will explore the clarity of
judicial independence, particularly following the Constitutional Reform Act 2005.1
The separation of powers is a mechanism for enforcing the institutional separation of
government into executive, legislative, and judicial branches, appointing the respective
governmental functions and dividing personnel. These three elements serve to promote
government efficiency, prevent tyranny through the avoidance of concentrations of power,
and preserve liberty “from the oppressive, arbitrary, or violent intention of those who wield
government power”.2
However, the doctrine requires the distribution of equal governmental power which is
incompatible with parliamentary sovereignty, the “bedrock of the British Constitution”, 3 as it
1
Constitutional Reform Act 2005
2
Robert Masterman, and Colin Murray, Constitutional and Administrative law (2nd edn, Pearson 2018) 224
3
Jackson v Attorney General [2005] UKHL [9] (Lord Bingham)
, permits little opportunity for the restriction of the legislature’s unfettered authority. 4 This
undermines the separation of powers as it makes judges submissive to parliamentary will
whilst strengthening the political branches to the detriment of the judiciary. 5 Therefore, to
claim there to be an equilibrium of power between the governmental branches, or even an
equal system of checks and balances is unconvincing6 due to the impossibility of the
separation of powers existing when the constitution confers “absolute power… on our
sovereign body”.7
Whilst the pure theory advocates a strict and complete divide of personnel, functions, and
institutions, the partial model allows a degree of interaction between the branches to
balance their power and hold them “adequately to account”. 8 The severity of the pure
theory raises criticisms of a “paradox” lying “at the heart of the doctrine” 9 as it does not
allow the possibility of checks and balances, resulting in a limitation of both liberty and
efficiency. Therefore, the flexibility provided by the partial theory is often preferred despite
the increased risks of collusion or tyranny, like the UK’s latent “elective dictatorship,10 and
loss of specialisation. A realistic assessment of the UK’s separation of powers reveals that
“all three branches of government effectively perform all three functions”. 11
4
Roger Masterman, and Se-shauna Wheatle, 'Unpacking separation of powers: Judicial Independence,
Sovereignty and Conceptual Flexibility in the UK constitution.' [2017] PL 469, 472
5
Diana Woodhouse, 'The English Judges, Politics and The Balance of Power' (2003) 66 MLR 921
6
Robert Stevens, The English Judges: Their Role in the Changing Constitution (Hart Publishing, 2005) 97
7
BBC, 'The Richard Dimbleby Lecture: Lord Hailsham: Elective Dictatorship' (1976)
8
Eric Barendt, ‘Separation of Powers and Constitutional Government’ [1995] PL 599, 607
9
Mark Elliott and Robert Thomas, Public Law (4th edn, OUP 2020) 110
10
BBC, 'The Richard Dimbleby Lecture: Lord Hailsham: Elective Dictatorship' (1976)
11
Peter Cane, Administrative Law (4th edn, Clarendon Press, 2004)